Directions

Make the cake in a 13x9-inch baking pan following instructions on the box of cake mix (Preheat oven to 350 degrees; mix cake mix, water, oil, and eggs together in a large bowl; pour batter into pan greased generously with shortening.).

Allow the cake to cool completely.

When cake is cool, make buttercream frosting by first whipping the soft butter in a large bowl with an electric mixer on high speed.